Apparatus for manufacturing rayon



Nov. 29, 1938.

W. WUPPERMANN APPARATUS FOR MANUFACTURING RAYON Filed Nov. 3, 1936 2 Sheets-Sheet 1 M wNA W. WUPPERMANN APPARATUS FOR MANUFACTURING RAYON Nov. 29, 1938.

Filed Nov. 5, 1956 2 Sheets-Sheet 2- Patented Nov. 29, 1938 UNITED STATES PATENT OFFICE Wilhelm Wuppermann, Berlin-Zehlendorf, Germany Application November 3, 1936, Serial No. 108,952 In Germany Ncvember 9, 1935 10 Claims.

My invention relates to improvements in apparatus for manufacturing rayon, and more particularly in apparatus of the type in which the spinning apparatus comprises a nozzle through which the viscose or the like is ejected and a container for the coagulating bath, the said nozzle and container being concentrically arranged and rotatable during the spinning operation, and means being provided for supplying the viscose and the coagulating bath to the said nozzle and container, and for collecting the thread rising from the said container on a suitable collecting device such for example as a bobbin.

One of the objects of the improvements is to provide an apparatus of this type in which the filaments ejected through the nozzle are sufficiently coagulated within the container before leaving the same and being twisted, so that the filaments do not stick to one another and a pliant thread is produced. With this object in view my invention consists in providing a cylindrical container in the form of an elongated pipe having a length such that the filaments moving through the container and the coagulating bath contained therein have sufficient time to be coagulated by the coagulating bath, and, further, providing means for maintaining the coagulating bath within the contain-er under pressure and so that it completely fills the container substantially to the top end thereof and so as to avoid, practically, the formation by centrifugal action of a paraboloid at the top of the bath, the said means consisting in supplying the Whole coagulating bath under pressure to the bottom part of the said container through a passage or passages in which it is made to assume the rotary velocity of the bath contained within the container before itis supplied thereto, and providing a delivery orifice at the top part of the container which is so small that the pressure produced by the incoming coagulating bath is sufficient substantially to prevent the formation of a paraboloid.

Another object of the improvements is to provide means for regulating the flow of the coagulating bath through the container in accordance with the strength of the thread to be produced, and with this object in view I provide the container at its top with a gauged nozzle the orifice of which is located concentrically of the container and has the filaments and the bath passed therethrough. 7

In the practice of the spinning apparatus I have found that the coagulating bath moving upwardly within the container loses in concentration at the part immediately surrounding the filaments, the reason being that the coagulating bath is diluted by the water contained in the viscose, and by the reaction with the viscose or the like, so that its specific gravity is reduced and the diluted bath tends to remain near the axis of the container by reason of the centrifugal force acting to throw the more concentrated coagulating bath outwardly and towards the wall of the container. Therefore, another object of the improvements is to provide means for supplying none-diluted coagulating bath to the filaments rising within thecontainer, and with this object in view my invention consists in providing a container which is reduced in cross-section from its bottom part surrounding the nozzle upwardly, and I have found that a reduction of the cross-section of the container to about 2 square centimeters is sufficient, under normal conditions, for maintaining a sufiiciently concentrated spinning bath in contact with the filaments. However, under certain circumstances, and more particularly when the spinning velocity is high it is preferred further to reduce the cross-sectional area.

Other objects of the improvements will appear from the following description.

For the purpose of explaining the invention several examples embodying the same have been shown in the accompanying drawings in which the same reference characters have been used in all the views to indicate corresponding parts. In said drawings,

Fig. 1 is a sectional elevation showing the spinning apparatus,

Fig. 2 is a sectional plan view on an enlarged scale taken on the line 22 of Fig. 1,

Fig. 3 is a similar sectional elevation showing a modification,

Fig. 4 is an elevation showing a part of Fig. 2,

Fig. 5 is a sectional elevation of the bottom part of a spinning apparatus showing a modification of the shaft for supplying the viscose and its mounting,

Fig. 6 is a similar sectional elevation showing another modification,

Fig. 7 is a sectional elevation on an enlarged scale showing a slightly modified construction of the chamber through which the coagulating liquid is supplied, and

Figs. 8 to 11 are similar sectional elevations showing modifications.

In the example shown in Fig. 1, the spinning apparatus comprises a nozzle 5 provided with numerous fine orifices for the ejection of the viscose or similar liquid therethrough, the said nozzle being fixed to the top of a rotary shaft 2 by means of a sleeve 3 and a screw-cap 4. The shaft 2 is formed with a longitudinal bore for the supply of viscose to the nozzle i. To the shaft a pipe 5 is fixed at 6 and i which takes part in the rotary movement of the shaft, and which provides an annular passage 8 for the admission of a suitable coagulating bath, the said pipe being provided near its bottom part with openings 9 and at its top with inclined and outwardly directed delivery passages Ill. The pipe 5 carries a cup Ii surrounding the nozzle i. To the cup E! a tubular container I2 is secured by means of a screw-cap i3, which tubular container tapers inwardly from its bottom to its top. For the reasons to be explained hereafter, the tubular container l2, as it is illustrated in Fig. 1, has a comparatively large cross-sectional area at its bottom part, is reduced to a comparatively small cross-sectional area which is about 2 square centimeters, and which is gradually reduced from a part slightly above the cup ll to its top end. It will be understood. that the viscose or similar material is delivered through the nozzle l and the tubular container I2, so that it is carried upwardly therein by the coagulating bath supplied through the passages 8 and ID, the filaments or the thread formed from the viscose by coagulation being carried upwardly to a collecting device, such as a bobbin l4, and the coagulating bath being delivered from the tubular container 2 at the ,top thereof, where it is subject to centrifugal action and is collected by a receptacle comprising an upper section l5 and a lower section it, the lower section 16 being provided with a delivery pipe I! through which the bath is conducted to a receptacle in which it may be regenerated. Connected to or made integral with the cup H is a conical flange 58 which is directed downwardly therefrom so as to prevent access of the coagulating liquid to other parts of the apparatus in which the shaft 2 and the parts carried thereby are mounted, as will now be described.

The apparatus comprises a cylindrical casing 22 in which an electro-motor 23 is mounted the armature 24 of which is fixed to a tubular shaft 25. This shaft is mounted in anti-friction bearlugs 26 provided in a cylindrical casing 21 extending downwardly from the casing 22. To the bottom part of the said tubular shaft 25 the shaft 2 is fixed with a slightly tapering bottom end 28, nuts 29 being provided for holding the shaft in position. A downwardly directedextension 38 of the shaft 2 is in loose engagement with a step bearing 3! which is guided in an extension 32 of the casing 2! and acted upon by a spring 33 tending to-hold the same in tight engagement with the extension 30 of the shaft 2. A tubular extension 34 of the step bearing 3| is connected with the supply of viscose or other material.

The shaft 2 is passed through an elastic ring 35 of felt or similar material which is carried by the top part of cover 36 of the casing 22.

on the said top part 35 a tubular member 31 is mounted in which a concentric ring 38 is embedded which provides an annular passage 39 with the bottom part of the pipe 5, the said annular passage communicating with the aforesaid openings 9. At its top and bottom the said annular passage is closed by disks 40 of elastic material such as rubber. In Fig. 7 I have shown a slightly modified construction of the said disks on an enlarged scale. As is shown in the said figure, the said disks are Z-shaped in crosssection and they have annular flanges 4| disposed around the pipe 5. I have found that the said annular flanges may (unless provision to prevent is made) be deformed by the pressure of the coagulating bath, into more or less oval shape, so that passageway may open between the said annular flanges and the exterior surface of pipe 5, through which much coagulating bath will escape. Therefore I reinforce the said annular flanges by rings 42 of solid material such as artificial resin or a suitable metal.

In Figs. 2 to 4 I have shown in detail the supply of the coagulating bath to the annular passage 8, the supply being constructed so that whirls of the liquid within the passage 8 are as far as possible avoided, and the resistance opposed to the admission of the liquid to the passage 39 is reduced.

In the construction shown in Fig. 2 a pipe 5| is connected to the annular chamber 39 in tangential direction and so that the bath is delivered into the said chamber in the direction of the rotation of the spinning head, as is indicated by arrows ,f. The passages 9 made in the pipe 5 are curved from the outer circumference and in the direction of the rotation inwardly, so that the bath is delivered into the annular passage 8 in tangential direction. Thus the liquid is delivered into the passage 8 with a certain velocity which is more or less equal to the circumferential velocity of the walls of passage 8. The blades formed in the pipe 5 by the passages 9 are pointed at both ends as is indicated at r and s.

In the example shown in Fig. 2 both walls of the passages 9 are curved. In the modification shown in Fig. 3 only the convex walls of the said passages 9 are curved, while the opposite walls are plane and tangential to the outer cylindrical wall of the passage 8.

In Fig. 4 I have shown the distribution of the passages 9 around the pipe 5.

Within the passage 8 the liquid assumes the velocity of the passage walls while flowing upwardly therein, and in order to make sure that the liquid leaving the passage 3 has the same circumferential velocity as the pipe 5, ribs 52 may be provided on the wall of the pipe 5.

Above the delivery end of the tubular container i2 there is a thread guide 52 which is fixed to the said container and which has the function to prevent twisting of the filaments within the container. Above the said rotary thread guide a stationary thread guide 54 is provided, through which the thread is passed before it is Wound on the bobbin. As shown the said thread guide is fixed to the container section l5. Its object is to prevent the thread from bulging outwardly between the thread guide and the bobbin l 4. V

In the operation of the apparatus the shaft 2 and the spinning head carried thereby are rotated' at a velocity suihcient to give the desired twist to the thread being formed from the viscose, The supply of the coagulating bath is opened,

and the said bath supplied to the passage 39 is under pressure, so that it flows through the tubular container I2 with a certain head. The viscose is supplied under pressure through the pipe 34, and it is delivered through the nozzle I and into the said container [2, where it is formed into filaments rising with the coagulating bath. The rotary velocity of the bath is equal to that of the filaments, and therefore the said filaments are not twisted within the tubular container E2, the length of the said container being sufficient to cause coagulation of the filaments before they pass through the thread guide. By the said thread guide the rotary movement imparted to the filaments by the rotation of the nozzle and the coagulating bath within the container I2 is interrupted, and the portion of the thread moving from the thread guide to the bobbin does not rotate. Therefore the filaments are twisted into a thread when they arrive in the thread guide. The length of the tubular container I2 and other conditions of the spinning apparatus are such that the filaments are coagulated before they are twisted into a thread.

For starting the spinning operation, the section I5 and the tubular container I2 are removed from the spinning head, the supplies of the viscose and the coagulating bath are opened until the coagulating bath fills the section it and the cup I I. The viscose is delivered from the nozzle I in the form of a bundle of filaments. The container I2 and the section I5 are now placed respectively on the cup II and the section I5, and the coagulating bath rises within the container I2 carrying along the filaments. If necessary, the filaments may be pulled upwardly by means of a hook passed into the tubular container I2 from the top thereof.

In the practice of the invention'I have found the following points to be particularly important:

First, the length of the tubular container I2 must be such that the filaments are sufficiently coagulated before they get to the thread guide 52. By centrifugal action the liquid has the tendency to form a parabolic surface, so that the active length of the container i2 is reduced by the axial length of the paraboloid thus formed. For this reason the top or delivery end of the container I2 is reduced in diameter. Thereby the axial length of the paraboloid is reduced. Another expedient consists in supplying the coagulating bath under a pressure sufii" cient. .tocause the coagulating bath delivered from the top part of the container I2 completely to fill out the cross-sectional area of the delivery end, in which case the full height of the container I2 is made use of.

Another important feature of the apparatus shown in Fig. 1 is the shape of the container I2 which is reduced in cross-sectional area slightly above the nozzle, and which further tapers inwardly towards its delivery end. I have found that the coagulating bath has not its full coagulating action on the filaments when a container I2 of comparatively large cross-sectional area is used, and in my opinion this fact is explained by centrifugal action in connection with the specific gravity of the coagulating bath, which is high in case of a bath of high concentration and low in case of a bath of low concentration.

The water contained in the viscose filaments rising within the container I2 dilutes the coagulating bath immediately surrounding the filaments and thus reduces the specific gravity thereof. Further, the specific gravity of the said part of the bath is reduced by reaction with the viscose. The part of the coagulating bath ofhigher specific gravity remains near the wall of the container I2, and therefore the bath acting on the filaments is not regenerated. By reduction of the cross-sectional area of the container I 2 this objection is obviated.

Another important feature of my spinning apparatus consists in supplying the coagulating bath to the container I2 so that its velocity in circumferential direction is the same as that of the container and the filaments ejected from the nozzle I, and that no whirls are produced in the coagulating bath which would tear the filaments. These results are-attained by the aforesaid construction of the passages for supplying the coagulating bath, whereby the said bath has the full circumferential velocity of the spinning head as it leaves the passages I0. Thus there is no relative movement between the coagulating bath and the filaments in circumferential direction.

As has been stated before, the conditions to which the coagulating bath is subjected should be such that the container is completely filled up to its top and that practically no paraboloid is formed. Now it is desirable'to regulate the conditions. More particularly the flow of the coagulating, bath must be regulated in accordance with thetiter of the thread to be produced. Therefore I prefer to provide several gauged nozzles 55 adapted to be fixed to the delivery end of the container I2,'so that the cross-sectional area. of the delivery end may be adapted to various conditions.

As has been stated above, the shaft 2 is flexible so that the system may set itself with its center of gravitation in the axis of rotation. In Figs. 5 and 6 I have shown modifications of this construction.

In the construction shown in Fig. 5 the shaft is not flexible, but rigid, and it is adapted to set itself in position by being fixed within a ball 60 which is mounted in a spherical socket carried by the tubular shaft 25. As shown the said spherical socket comprises an upper semispherical portion 6| formed at the bottom end ofthe shaft 25 and a semi-spherical screw-cap 62 fixed to the bottom end of .the said shaft. The shaft I is extended downwardly, and at its bottom end it carries a block 63 having a spherical bottom face and sliding on a block 64 formed with a concave top face 65, the said block being mounted in the step bearing 3I and pressed into engagement with the block 53 by the spring 33. The bottom part of the shaft 2 carries a block 66 having a spherical top face engaging the spherical cap 62 and held in position by nuts 61.

In the modification shown in Fig. 6 the shaft 68 is flexible, the same as the shaft 2 shown in Fig. 1, but it is mounted near the top and bottom part of the tubular shaft 25 in balls I and II, the said balls being in engagement with cylindrical bearing faces 12 and 13 provided on the inner wall of the shaft 25. The shaft 68 is fixed within the balls "I0 and 'II by tapering portions I4 and I5 and nuts 11 and I8. By reason of its flexibility the shaft 68 may be bent in the operation of the apparatus so that the center of gravitation of the system is located in the axis of rotation, Fig. 6 indicating the deformed shaft 88 exaggerated in dashes and dots I9.

It will be, understood that the parts of the mounting of the shafts 2, 68 and 25 are similar to the corresponding parts described with reference to Fig. 1, and therefore a detailed description of these parts is not necessary.

In Figs. 9 to 11 I have shown modifications of the packing rings 40 confining the annular chamber 39 at its ends.

In the construction shown in Fig. 8 the elasticity of the said packing disks is increased by providing therein an annular portion iii of U.- shaped cross-section in lieu of the Z-shaped portion shown in Fig. 7. Otherwise the construction of the disk is the same as that described with reference to Fig. 7, and the same reference characters have been used to indicate corresponding parts.

In the modification shown in Fig. 9 the packing disk is provided with two angular portions 82 connected at their ends respectively with the top and bottom part of the flange 45-, one of the '15 said angular portions being provided with one or more holes 83.

In the modifications shown in Figs. 10 and 11 the solid reinforcing ring 42 is provided respectively on the inner and outer wall of the flange 4|.

In all the modifications the annular flanges are in tight engagement with the wall of the pipe 5, Without however exerting high pressure thereon. Thus the rings are sufficiently tight without unduly increasing the resistance by friction of the rotating pipe 5. V

In the practice of the invention I have found that the flow of the coagulating liquid through the apparatus is subject to variation, particularly where numerous spinning apparatuses are connected to the same supply of the coagulating liquid. The resistance opposed to the flow of the liquid within the apparatus varies, particularly when one or more spinning apparatus are temporarily thrown out of operation. Thereby the uniformity of the threads produced by all the apparatus is impaired. To avoid this objection I have provided means in connection with each apparatus for measuring and regulating the amount of coagulating liquid supplied to the apparatus. As is shown in Fig. 1, the delivery pipe I! includes a three-way cock through which the coagulating liquid may be filled into a measuring receptacle 86. Further, the intake pipe 51 includes a regulating valve 81.

.In the operation of the apparatus the attendant will from time to time set the three-way cock 35 into position for delivering the coagulating bath for a certain period of time into the measuring receptacle 86, and he will regulate the supply of liquid by means of the cook 81 accordingly.

I claim:

1. An apparatus for spinning rayon, comprising a rotatably mounted nozzle, means for supplying to said nozzle viscose or other spinning liquid under pressure, a rotatably mounted tubular container in which said nozzle is located at one end, said tubular container having itsend remote from said nozzle contracted, means for supplying a coagulating liquid to said container at the end thereof near the nozzle and for' maintaining said container filled with such liquid under pressure, means for imparting rotary movement to said nozzle and to said container, and a thread guide borne by said container beyond the delivery end of said container, the contracted portion of said container and the means for supplying the coagulating bath being such that the resistance opposedby said contracted portion to the flow of the coagulating bath and the pressure imparted to the coagulating bath are sufiicient substantially to prevent the formation by centrifugal action of a parabolic surface of the coagulating bath within said container, and the length of said rotary container being sufiicient to cause coagulation of the filaments so farthat sticking together of the said filaments being .collected is prevented.

2. An apparatus as claimed in claim 1, in which the container is gradually reduced in cross-section from the end surrounding said nozzle to the end remote therefrom.

3. An apparatus as claimed in claim 1, in which the container comprises a portion near said nozzle which is abruptly reduced in crosssection and a tapering portion extending from the said reduced cross-section to the end of said container remote from the nozzle.

4. An apparatus as claimed in claim 1, in which a stationary thread guide is provided in front of the delivery end of said container.

5. An apparatus as claimed in claim 1, in which the said containeris a two-part structure of which the lower part forms a cup whose rim is disposed in a horizontal plane at higher level than the nozzle and of which the upper part is removably mounted upon the rim of the cup of the lower part.

6. An apparatus as claimed in claim 1, comprising a rotary shaft on which said nozzle is mounted, said shaft having a bore for the supply of viscose therethrough, a pipe disposed concentrically of and fixed to said shaft in a lower portion of its extent and providing an annular passage therewith, said pipe being provided with orifices for the delivery of the coagulating bath into the said container, a cylindrical stationary member around said pipe providing an annular said shaft permitting play of the shaft relatively to the rotating means and transversely of the axis of the shaft. a

8. Apparatus as claimed in claim 1, comprising a rotary shaft carrying said nozzle and-having a bore for the supply of viscose or other spinning material therethrough, stationary means for supplying the viscose to the bore of said shaft, said stationary means making yielding engagement with said shaft, a ball in which said shaft is fixed near the end remote from said nozzle, and a spheric socket in which said ball is loosely mounted.

9. Apparatus as claimed in claim 1, comprising a flexible shaft carrying said nozzle and having a bore for the supply of viscose or other spinning material therethrough, stationery means for supplying the viscose-to the bore of said shaft, said stationary means making yielding engagement with said shaft, and a pair of loosely mounted balls fixed to said shaft near the end remote from said nozzle and spaced from each other, and bearings for said balls permitting oscillating movement of the shaft. 7

10. Apparatus for spinning rayon comprising a hollow shaft standing vertically and'resting upon a ported bearing-block and equipped at its upper end with a nozzle, a bearing within which the shaft is rotatable and engaging the shaft in the upper portion of its extent, an electro-motor structure including an armature that surrounds the shaft in the lower portion of its extent andwith which the shaft is united, the inner diameter of the armature exceeding the outer diameter of the shaft and the armature being spaced from the shaft, whereby when the parts are in rotation the shaft may adjust itself in its position Within the armature.

WILHELM WUPPE RMANN. 

